Five ways butterflies survive the winter.
Nature is endlessly inventive. When faced with a challenge she responds with a variety of solutions. For example, animals and plants exhibit a remarkable range of responses to the challenge of winter.
Butterflies illustrate this, having evolved no fewer than five ways to respond to the killing cold. Some escape south as many birds do. The magnificent autumnal flight of monarchs from Canada to Mexico is the best known example of this solution. But other butterflies migrate south as well, including red admirals and American ladies.
Some of our butterflies pass the winter as chrysalides. These exquisite capsules of possibility are lashed with silken thread to branches and other supports. Within, the dormant pupae rest until energized by spring warmth. Our swallowtails have “chosen” this solution to the problem of winter.
Viceroys, white admirals, fritillaries and most skippers overwinter as caterpillars, likely relying on some type of “antifreeze” to prevent complete freezing – a strategy also used by some of our frog species.
Still other butterflies overwinter as eggs. The tiny but exquisite hairstreak butterflies do this, as does the European skipper.
The least frequent solution to winter among our butterflies is to hibernate as adults. Commas, mourning cloaks and Compton tortoiseshells hide under peeling bark or woody debris on the forest floor to wait out the winter.
Then, on warm sunny days as early as March, they emerge to bask in the sun. What a welcome sight they are! Splashes of warm colour accenting the sombre late winter woodland.
Flying before the nectar of woodland wildflowers is available poses another challenge – where to find nourishment. For these butterflies the solution is to drink sap leaking from the wounds of winter damaged trees or from punctures in bark made by the pounding beaks of yellow-bellied sapsuckers.
Problem posed, problem solved, by the endless inventiveness of nature.